Last

java.lang.Object

org.projog.core.predicate.AbstractPredicateFactory

org.projog.core.predicate.builtin.list.Last

All Implemented Interfaces:: KnowledgeBaseConsumer, PredicateFactory

public final class Last extends AbstractPredicateFactory

last(X,Y) - finds the last element of a list.

Nested Class Summary

Nested Classes

Modifier and Type

Class

Description

private static final class

Last.LastPredicate
Constructor Summary

Constructors

Constructor

Description

Last()
Method Summary

Modifier and Type

Method

Description

protected Predicate

getPredicate(Term list, Term termToUnifyLastElementWith)

boolean

isRetryable()

Should instances of this implementation be re-evaluated when backtracking?

Methods inherited from class AbstractPredicateFactory
getArithmeticOperators, getFileHandles, getKnowledgeBase, getOperands, getPredicate, getPredicate, getPredicate, getPredicate, getPredicate, getPredicates, getProjogListeners, getSpyPoints, getTermFormatter, init, setKnowledgeBase

Methods inherited from class Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface PredicateFactory
isAlwaysCutOnBacktrack

Constructor Details
- Last
  
  public Last()
Method Details
- getPredicate
  
  protected Predicate getPredicate(Term list, Term termToUnifyLastElementWith)
  
  Overrides:
  
  getPredicate in class AbstractPredicateFactory
- isRetryable
  
  public boolean isRetryable()
  
  Description copied from interface: PredicateFactory
  
  Should instances of this implementation be re-evaluated when backtracking?
  Some goals (e.g. X is 1) are only meant to be evaluated once (the statement is either true or false) while others (e.g. repeat(3)) are meant to be evaluated multiple times. For instances of Predicate that are designed to possibly have Predicate.evaluate() called on them multiple times for the same individual query this method should return true. For instances of Predicate that are designed to only be evaluated once per individual query this method should return false.
  
  Specified by:
  
  isRetryable in interface PredicateFactory
  
  Overrides:
  
  isRetryable in class AbstractPredicateFactory
  
  Returns:
  
  true if an attempt should be made to re-evaluate instances of implementing classes when backtracking, false otherwise